International Research Journal of Engineering and Technology (IRJET) Volume: 03 Issue: 08 | Aug-2016
www.irjet.net
e-ISSN: 2395 -0056 p-ISSN: 2395-0072
An Efficient Hybrid System for Speed Control of Brushless DC Motor Sunil Kumar1, Ajay Kumar2 1M.Tech
2Associate
Scholar, Electrical Engineering Department, BUEST Baddi, Himachal Pradesh, India Professor, Electrical Engineering Department, BUEST Baddi, Himachal Pradesh, India
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Abstract - The conventional control techniques cannot
fulfill the most important needs to optimize dynamic systems, electronic circuits, and industrial processes. Brushless DC motors (BLDC) find wide applications in industries due to their high power density and ease of control. These motors are generally controlled using a three phase power semiconductor bridge. For starting and providing proper commutation sequence to turn on the power devices in the inverter bridge the rotor position sensors are required. Based on the rotor position, the power devices are commutated sequentially every 60 degrees. To achieve desired level of performance the motor requires suitable speed controllers. In case of motors, usually speed control is achieved by using Proportional (P), Proportional integral (PI), PID & fuzzy logic (FL) controller. According to new proposed approach speed control of BLDC motor drive and analysis using hybrid PID-fuzzy logic controller to carry off the weakness of fuzzy logic controller ( Steady-state error ) and PID controller( Overshoots, Undershoots). The proposed hybrid PID-fuzzy logic controller is evaluated via computer simulation using MATLAB simulator. Key Words: Brushless DC Motor (BLDC), Proportional Integral (PI), Fuzzy Logic Controller (FLC), MATLAB.
1. INTRODUCTION Brushless dc (BLDC) motors are preferred as small horsepower control motors due to their high efficiency, silent operation, compact volume, long operating life, high speed response, high output power, reliability, and low maintenance. However, the problems are encountered in these motor for variable speed operation. Over last decades, continuing technology development in power semiconductors, microprocessors, adjustable speed drivers control schemes and permanent-magnet brushless electric motor production have been combined to enable reliable, cost-effective solution for a broad range of adjustable speed applications. Household appliances are expected to be one of fastest-growing end-product market for electronic motor drivers over the next five years. The major appliances include clothes washers, room air conditioners, refrigerators, vacuum cleaners, freezers, etc. Household appliance have traditionally relied on historical classic electric motor technologies such as single phase AC induction, including split phase, capacitor-start, capacitor– Š 2016, IRJET
run types and universal motor. These classic motors typically are operated at constant-speed directly from main AC power without considering the efficiency. Consumers now demand for lower energy costs, better performance, reduced acoustic noise, and more convenience features. Those traditional technologies cannot provide the solutions.
2. BLDC Motor Applications BLDC motors find applications in every segment of the market. Some of the applications are described below: i) Consumer: PC cooling fans, washing machine, vacuum cleaner, air conditioner, refrigerator, toys. ii) Medical: artificial heart, microscopes, centrifuges, dental surgical tools, organ transport pump system. iii) Automobile: automotive applications, electric and hybrid vehicle etc. We can categorize the BLDC motor control into three major types such as a) Constant load b) Varying loads c) Positioning applications
a) Constant Loads For single-speed applications, induction motors are more suitable, but if the speed has to be maintained with the variation in load, then because of the flat speed-torque curve of BLDC motor, BLDC motors are a good fit for such applications.
b) Varying Loads BLDC motors become a more suitable fit for such applications because variable speed induction motors will also need an additional controller, thus adding to system cost.
c) Positioning Applications BLDC motors used in Position control application require more complex controller, optical encoders or High resolution resolvers to calculate speed of motor, two or more closed loop are operated simultaneously.
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